Ilumination apparatus

• US 10,605,434 B2
• Filed: 06/26/2019
• Issued: 03/31/2020
• Est. Priority Date: 10/21/2010
• Status: Active Grant

• Current Assignee: Optovate Ltd. (Reald Spark, LLC)
• Original Assignee: Optovate Ltd. (Reald Spark, LLC)
• Inventors: Woodgate, Graham J., Harrold, Jonathan
• Primary Examiner(s): Bowman, Mary Ellen
• Application Number:
  US16/453,298
• Publication Number:
  US 20190316761A1
• Time in Patent Office: 279 Days
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21K 9/69 Details of refractors forming part of the light source
• CPC Class Codes: F21K 9/90 Methods of manufacture
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 17/00 Fastening of component parts of lighting devices, e.g. shades, globes, refractors, reflectors, filters, screens, grids or protective cages of light sources or light holders F21V19/00
• CPC Class Codes: F21V 23/002 Arrangements of cables or conductors inside a lighting device, e.g. means for guiding along parts of the housing or in a pivoting arm
• CPC Class Codes: F21V 5/007 Array of lenses or refractors for a cluster of light sources, e.g. for arrangement of multiple light sources in one plane combination of two or more refractors F21V5/008
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21Y 2101/00 Point-like light sources
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: G02F 1/133612 Electrical details
• CPC Class Codes: G09G 3/2088 with use of a plurality of processors, each processor controlling a number of individual elements of the matrix
• CPC Class Codes: H01L 21/268 : using electromagnetic radiation, e.g. laser radiation
• CPC Class Codes: H01L 22/20 : Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• CPC Class Codes: H01L 2224/16225 : the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 24/32 : of an individual layer connector
• CPC Class Codes: H01L 25/0753 : the devices being arranged next to each other
• CPC Class Codes: H01L 25/167 : comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12035 : Zener diode
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/1301 : Thyristor
• CPC Class Codes: H01L 2924/13033 : TRIAC - Triode for Alternating Current - A bidirectional switching device containing two thyristor structures with common gate contact
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/15788 : Glasses, e.g. amorphous oxides, nitrides or fluorides
• CPC Class Codes: H01L 2924/3512 : Cracking
• CPC Class Codes: H01L 2933/0033 : relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 : relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/005 : relating to encapsulations
• CPC Class Codes: H01L 2933/0058 : relating to optical field-shaping elements
• CPC Class Codes: H01L 2933/0066 : relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/0093 : Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/0095 : Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/08 : with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/504 : Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/56 : Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 : Optical field-shaping elements
• CPC Class Codes: H01L 33/60 : Reflective elements
• CPC Class Codes: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: Y10T 29/49117 : Conductor or circuit manufacturing

Abstract

An illumination apparatus comprises a plurality of LEDs aligned to an array of directional optical elements wherein the LEDs are substantially at the input aperture of respective optical elements. An electrode array is formed on the array of optical elements to provide at least a first electrical connection to the array of LED elements. Advantageously such an arrangement provides low cost and high efficiency from the directional LED array.

Claims

1. A method for manufacturing an illumination apparatus, the method comprising:

forming a first monolithic array of light-emitting elements;

determining a first plurality of the light-emitting elements which pass a functional criterion;

determining a second plurality of the light-emitting elements which fail the functional criterion;

selectively removing a plurality of the passed light-emitting elements whose relative positions in the first monolithic array correspond to desired relative positions in a desired non-monolithic array of light-emitting elements, the selectively removing being performed in a manner that preserves the relative spatial position of the selectively removed passed light-emitting elements;

wherein the plurality of passed light-emitting elements that are selectively removed from the monolithic array are selected such that, in at least one direction, for at least one pair of the selectively removed passed light-emitting elements in the at least one direction, for each respective pair there is at least one respective light-emitting element that is not selected that was positioned in the monolithic array between the pair of removed passed light-emitting elements in the at least one direction; and

forming a non-monolithic array of light-emitting elements with the selectively removed passed light-emitting elements in a manner that preserves the relative spatial position of the selectively removed passed light-emitting elements, by virtue of which in the formed non-monolithic array of light-emitting elements desired relative positions of the desired array that correspond to passed light-emitting elements in the first monolithic array are occupied by passed light-emitting elements, and desired relative positions of the desired array that correspond to failed light-emitting elements in the first monolithic array are left unoccupied.

2. The method according to claim 1, wherein further light-emitting elements are added to the formed non-monolithic array of light-emitting elements in unoccupied desired relative positions of the desired array.

3. The method according to claim 2, wherein the further light-emitting elements have been determined as passing the functional criterion.

4. The method according to claim 2, wherein the further light-emitting elements are from the first monolithic array of light-emitting elements.

5. The method according to claim 2, wherein the further light-emitting elements are from a second monolithic array of light-emitting elements that is different to the first monolithic array of light-emitting elements.

6. The method according to claim 1, wherein the functional criteria includes at least one of intensity, colour, forward voltage or defect density.

7. The method according to claim 1, wherein the first monolithic array of light-emitting elements is made of a plurality of layers on a substrate, the light-emitting elements being inter-connected in the layers they are formed in, and

wherein selectively removing the plurality of light-emitting elements comprises selectively illuminating the plurality of the light-emitting elements with an illumination that separates, at least to an extent, the selected light-emitting elements from the substrate.

8. The method of claim 7, wherein the illumination further breaks the connection in the layers between each selectively illuminated light-emitting element and the other light-emitting elements.

9. The method of claim 7, wherein the connection in the layers between each selectively illuminated light-emitting element and the other light-emitting elements is broken at least to an extent by at least one of a scribing step, an ablation step or an etch step.

10. The method according to claim 7, wherein the selective illumination comprises a plurality of shaped laser beams.

11. The method according to claim 7, where the selective illumination comprises electromagnetic radiation in the ultraviolet wavelength band.

12. The method according to claim 7, wherein the substrate permits transmission of electromagnetic radiation therethrough.

13. The method according to claim 7, further comprising providing a patterned support layer formed on the plurality of light-emitting elements.

14. The method according to claim 7, wherein the light-emitting elements which fail the functional criterion are not illuminated or are illuminated below a threshold illumination level.

15. The method according to claim 7, wherein a light intensity reduction region is formed on a surface of the substrate, the light intensity reduction region being aligned with at least one of the second plurality of light-emitting elements.

16. The method according to claim 15, wherein the light intensity reduction region is arranged to absorb, diffuse or reflect the selective illumination such that the power density at the surface of the substrate falls below a threshold.

17. The method according to claim 1, further comprising aligning the non-monolithic array of light-emitting elements with an array of optical elements.

18. The method according to claim 1, wherein the light-emitting elements each have a maximum dimension of 0.1 mm or less.

19. A method for manufacturing an illumination apparatus comprising:

forming a first monolithic array of light-emitting elements;

characterising the first monolithic array of light emitting elements to provide a pass distribution and a fail distribution of light emitting elements;

selectively removing a plurality of passed light-emitting elements from the first monolithic array in a manner that preserves the relative spatial position of the selectively removed passed light-emitting elements;

forming a non-monolithic array of light-emitting elements with the selectively removed passed light-emitting elements in a manner that preserves the relative spatial position of the selectively removed passed light-emitting elements;

wherein the plurality of passed light-emitting elements that are selectively removed from the first monolithic array are selected such that, in at least one direction, for at least one pair of the selectively removed passed light-emitting elements in the at least one direction, for each respective pair there is at least one respective light-emitting element that is not selected that was positioned in the first monolithic array between the pair of passed selectively removed light-emitting elements in the at least one direction;

selectively removing a second plurality of light-emitting elements from a monolithic array of light emitting elements wherein the second plurality of light-emitting elements are arranged with at least part of the fail distribution in a manner that preserves the relative spatial position of the selectively removed second plurality of light-emitting elements; and

interspersing the second plurality of light-emitting elements with the first plurality of passed light-emitting elements to provide a corrected non-monolithic array of light emitting elements.

20. The method according to claim 19, further comprising forming a light intensity reduction region on a surface of the monolithic array support substrate aligned with the respective fail distribution of light emitting elements.